2015 Infiniti Q50 3.7 Performance Upgrades

So, you're looking to boost the performance of your 2015 Infiniti Q50 3.7? Excellent choice! These cars are fantastic platforms with a lot of potential hiding under the hood. While the VQ37VHR engine is already a solid performer, there's definitely room for improvement, whether you're aiming for better acceleration, sharper handling, or just a more engaging driving experience. Let's dive into some common issues owners face and explore practical upgrade solutions.

Addressing Common Performance Issues

Before throwing parts at your Q50, it's essential to diagnose any existing problems that might be hindering performance. Here are a few culprits to consider:

Sluggish Throttle Response

Problem: Many owners complain about a noticeable delay between pressing the accelerator pedal and the engine's actual response. This can make the car feel less eager and responsive, especially in stop-and-go traffic.

Solution 1: Throttle Controller

A throttle controller, like those from Pedal Commander or Sprint Booster, modifies the signal from the accelerator pedal to the ECU, effectively reducing the perceived lag. These devices offer adjustable sensitivity levels, allowing you to tailor the throttle response to your driving style. Installation is typically plug-and-play, requiring no specialized tools or wiring.

Tools Needed: None (typically)

Approximate Cost: $200 - $400

Solution 2: ECU Tune

A custom ECU tune can remap the engine's parameters, optimizing fuel delivery, ignition timing, and throttle response. A reputable tuner can address the throttle lag directly and often unlocks additional horsepower and torque throughout the rev range. This is a more involved process than installing a throttle controller but offers potentially greater performance gains.

Tools Needed: Access to a laptop, tuning software (often provided by the tuner), OBDII scanner.

Approximate Cost: $500 - $1000 (depending on the tuner and dyno time)

Restricted Exhaust Flow

Problem: The factory exhaust system on the Q50 3.7 is designed for noise reduction and emissions compliance, which can restrict exhaust flow and limit engine performance.

Solution 1: Cat-Back Exhaust System

A cat-back exhaust system replaces everything from the catalytic converters back, typically including the mid-pipe and mufflers. These systems are designed to improve exhaust flow, reduce backpressure, and enhance the exhaust note. Look for reputable brands like Invidia, ARK Performance, or Stillen. Consider stainless steel construction for durability.

Tools Needed: Socket set, wrenches, penetrating oil (for rusted bolts), jack and jack stands, exhaust hanger removal tool (optional).

Approximate Cost: $800 - $1500 (plus installation if you're not doing it yourself)

Solution 2: High-Flow Catalytic Converters (HFCs)

If you're looking for even more performance, upgrading to high-flow catalytic converters can further reduce exhaust restriction. Be aware that HFCs may trigger a check engine light if not properly tuned or if they don't meet local emissions standards. Research your local laws before installing HFCs.

Tools Needed: Same as cat-back exhaust, plus oxygen sensor socket.

Approximate Cost: $500 - $1000 (per pair, plus installation and potential tuning)

Weak Intake System

Problem: The factory intake system can be restrictive, especially at higher RPMs, limiting the engine's ability to breathe efficiently.

Solution: Cold Air Intake (CAI)

A cold air intake replaces the factory airbox and intake tubing with a larger, less restrictive system designed to draw cooler air into the engine. This can result in improved horsepower and torque, particularly at higher RPMs. Popular options include Stillen Gen3 intakes and AEM intakes. Ensure the intake has a heat shield to prevent the engine from drawing in hot air from the engine bay.

Tools Needed: Socket set, screwdriver, pliers.

Approximate Cost: $300 - $500

Suspension and Handling Issues

Problem: The stock suspension, while comfortable, can feel soft and prone to body roll, especially during aggressive driving.

Solution 1: Lowering Springs

Lowering springs replace the factory springs with shorter, stiffer springs, lowering the car's center of gravity and improving handling. This reduces body roll and can give the car a more aggressive stance. Eibach and H&R are reputable brands. Remember that lowering springs will affect ride quality, making it firmer.

Tools Needed: Spring compressors, socket set, wrenches, jack and jack stands.

Approximate Cost: $200 - $400 (plus installation, which can be time-consuming)

Solution 2: Sway Bars

Upgrading the sway bars (also known as anti-roll bars) increases the car's resistance to body roll during cornering. Thicker sway bars provide a more significant improvement in handling. Install both front and rear sway bars for optimal results. Stillen and Hotchkis offer sway bar kits for the Q50.

Tools Needed: Socket set, wrenches, jack and jack stands.

Approximate Cost: $300 - $600 (per set, plus installation)

Solution 3: Coilovers

Coilovers offer the ultimate in suspension adjustability. They replace the entire strut assembly and allow you to adjust ride height, damping, and sometimes camber. This allows you to fine-tune the suspension for optimal performance on the street or track. BC Racing, Tein, and KW are popular coilover brands. Keep in mind that coilovers require more expertise to install and adjust properly.

Tools Needed: Socket set, wrenches, jack and jack stands, alignment tools (optional, but recommended).

Approximate Cost: $1000 - $3000 (plus installation and alignment)

Braking Performance

Problem: While the stock brakes are adequate for everyday driving, they can feel overwhelmed during aggressive driving or track days.

Solution 1: Performance Brake Pads

Upgrading to performance brake pads can significantly improve braking performance and reduce brake fade. Look for pads designed for your driving style, whether it's street performance or track use. Hawk Performance, EBC Brakes, and StopTech are well-known brands.

Tools Needed: Brake caliper tool, socket set, wrench.

Approximate Cost: $100 - $300 (per axle)

Solution 2: Stainless Steel Brake Lines

Stainless steel brake lines replace the factory rubber lines, which can expand under pressure, leading to a soft brake pedal feel. Stainless steel lines provide a more consistent and firm pedal feel, improving braking response.

Tools Needed: Wrench, brake line wrench, brake fluid, bleeder kit.

Approximate Cost: $100 - $200 (per set, plus installation and brake fluid)

Solution 3: Big Brake Kit (BBK)

A big brake kit replaces the entire brake system with larger rotors, calipers, and pads. This provides significantly improved braking performance, heat dissipation, and pedal feel. BBKs are a more expensive upgrade but offer the best possible braking performance. Brembo, StopTech, and Wilwood offer BBKs for the Q50.

Tools Needed: Socket set, wrench, brake line wrench, brake fluid, bleeder kit, torque wrench.

Approximate Cost: $2000 - $5000 (per axle, plus installation)

Final Thoughts

Upgrading your 2015 Infiniti Q50 3.7 is a great way to enhance its performance and driving enjoyment. Remember to prioritize upgrades based on your specific needs and budget. Always research products and choose reputable brands. Proper installation is crucial for safety and performance, so consider having a qualified mechanic perform the work if you're not comfortable doing it yourself. And most importantly, enjoy the enhanced driving experience!